In a groundbreaking study, researchers have successfully evolved microbial cultures with the ability to sense pH changes, providing new insights into how organisms adapt to environmental fluctuations. The findings shed light on hidden pH sensing abilities found in both lab-evolved bacteria and natural ecosystems, like Andean pathogens and coral symbionts.
Enhanced pH-Sensing Capabilities
The study was spearheaded by Sarah Worthan, Ph. D., a postdoctoral fellow at Vanderbilt University unveils discoveries of some wild adaptations in lab-driven evolution with microbial cultures. The ability to sense pH can be evolved in bacteria by the researchers so they can quickly react to changes in their environment
Not only does this discovery underscore the utility of lab-driven evolution; it also sent the team searching for similar mutations in nature. Researchers found that these mutations also manifest in emerging pathogens like Bartonella baciliformis, the causative agent of Carrion’s Disease in the Andean valleys of South America, and in coral symbionts — organisms benefiting from a mutualistic relationship but faced with trying pH changes in their environment.
Roles of Rho Protein and pH Sensing
The take home result from this work, they discovered a particular mutation in the Rho protein that is crucial for stopping RNA transcription. The research also discovered that an arginine amino acid, when modal iron levels cycle between feast and famine,’ is replaced with a histidine.
More recently, and compellingly so, arginine to histidine mutations have been discovered in cancers that allow a pH sensing property for some oncogenic proteins. These mutations are pH sensing and can inhibit Rho activity in an Instant to affect gene expression in bacteria.
The research was a collaborative effort between Bratton’s lab, and the labs of co-authors Benjamin H. D., and Marc Boudvillain, Ph. Two years ago, in what they now know was a pivotal moment for their work, Dr. Schirmer and Dr. Alfonsio Mecionis, PhD., sought to understand the implications of this Rho protein mutation. In a study using lab experiments and biochemical analyses, the researchers reveal how the mutation enables the Rho protein to detect???and react to??? changes in pH, which provides insights into how this puzzling adaptation might work.
Conclusion
This study provides some important insights, not just into how microbes adapt but also because microbes going about their business in the environment provide a beautiful real-world example of natural selection. From both lab-evolved bacteria and natural ecosystems, these pH-sensing abilities emphasize what a superpower this capability is in addition to revealing how resilient and adaptive these little critters are — especially when it comes to protons— as well as the beauty of interdisciplinary collaboration to solve puzzles that keep us in awe.
